I use a very old Computer Case at home, it has only 3 3.5 HDD slots, and hard to install.
Some days ago, I bought a Seagate 7200.12 1TB HDD (mmmm…, Seagate again >.<), and a HDD bracket. The bracket costs 7$, sounds cheap, let’s look it:
It comes with screws, for install 4 HDDs and fixate into case.
OK, this is two HDDs fixated on it, looks very nice:
Finally, in the case: